Flexible electrical conduit.



H. HANSEN.

FLEXIBLE ELECTRICAL CONDUIT.

APPLICATION mm MAR. 9. 1916.

1 ,285, 1 38 Patented Nov. 19, 1918.

HANS HANSEN, 0F BROOKLYN, NEW YORK, ASSIGNOR T0 EASTERN FLEXIBLE CONDUIT comm, 0F BROOKLYN, NEWYORIK, A CORPORATION QF NEW YORK.

FLEKELE ELECTRICAL CON'DUIT.

Widen of Letters Patent;

ratente e Now. is, rate;

Application filed March 9, i916. Serial lilo. 83,193r

' To an whom it may concern:

provide such a conduit which shall be noncollapsible, non-extensible. and have a smooth interior surface. and at the same time be economical to manufacture.

Experience in the use of conduits of this particular class has shown that it is essential to provide in the structure a resilient member or members arranged transversely to the axis of the conduit to form a supporting means to prevent the collapse or flattening of the tubing when flexed ininstalling the same around curves and bends, and to maintain a cylindrical form of conduit under the usual conditions of installation and use. A helical member composed of resilient material has usually been employed for this purpose, sometimes surrounding a tubular structure and sometimes inclosed within it. In the former case the turns or convolutions of the helical member must not be widely separated in order to support the inner tube against collapse. In order to accomplish this it has been customary to wind the helix so thatthe adiacent turns or convolutions are in close contact and form practically a continuousv wall. If this is not done, and the turns are spaced apart, they 4 may crowd together in places and become widely separated in others, leaving in the latter case no suitable sllDDort for the inner tube and thereby rendering it collapsible and worthless for the purpose designed. My

aim is to produce a conduit in which the helical member incloses an inner tube formed of a longitudinally folded strip, and where the turns of the helical member are separated but are locked and permanently held in a fixed relation to each other, there-- by the required support and greatly reducing the cost of-material and labor in the manufacture of the conduit. I

l accomplish these objects by inclosing a longitudinally folded strip of closely woven fabric within a supporting helix'of semifiexible material the convolutions of which are spaced apart, and interweaving-with the convolutions of the helixa series of flexible longitudinally laid' members also substan instead of singly. Bv embodying a longi-' tudinally folded fiat fabric lining, I am able The structure thus 7 to interweave the helices and longitudinal threads loosely and still prevent seepage of the compound to the interior of the tube.

In the accompanymg drawing in which like numerals of reference indicate correspending parts in the various figures there-- of, Figure 1 is a plan view of my preferred type of conduit partly broken away to show the construction. Fig. 2 is a similar view showing-a loose woven lining with paper backing. 3 is the flat fabric of close woven elements 8 folded longitudinally about a mandrel with the edges 4: and 5 abutting to form the lining of the conduit. 6 represents the supporting helices, and 7 the longitudinal interwoventhreads. 9 is the paper backing.

The manufacture 'of thestructure described presents no novel problem, and may 1 be accomplished by machinery well known to those skilled in the art of conduit menu-- facture. Detailed description of such machinery and the related processes is therefore deemed unnecessary. Y

What I claim and desire tosecu're by Letters Patent is:

1. A conduit ofthe character describedcomprisinga lining, a helix of semi-flexible material inclosing said lining. the convolutions of the helix being separated by substantial unfilled spaces, and a series of longitudinally disposed flexible members interwoven with said convolutions and maintain ing the spacing between the convolutions.

2. A conduit -of the character described comprising a longitudinally folded fiat fabric lining, a'helix of semi-flexible material inclosing said lining with the convolutions separated by subsfeantizfl unfilled spaces and a series 91 iongitudinafiy (iispasecl flexible members inerwaven with said nonvolutiens and maintaining the simcing of the convolutions.

3. A conduit 9f the character described comprising a 15mg, a helix cemposed @f SE11; 0:5 parallel Swazi-flexible strandsa ar ranged in parallel relation, the convohfisian s 01 "the set being; sepamtei by sufisstan 1 spa ses and 2 genes sf isngrimflr 116- msm a HANS HANSEN, 

